The study is a single-blind, single-treatment study in which each subject acts as his/her own control. Study subjects will be persons with Type 2 diabetes mellitus of five years' or less duration which has been treated, maximally, by diet, exercise, and less than a half-maximal dose of an oral anti-diabetic agent. In the study, 20 subjects will be removed from any anti-diabetic therapy and placed on an appropriate weight maintenance diet for the duration of the study. After an approximately 10-week acclimation period, study subjects will receive high(1800 mg) daily doses, orally, of a dietary supplement, alpha-lipoic acid (ALA), for 12 weeks. The effect of this treatment on blood glucose homeostasis will be assessed by statistical analysis of changes from baseline in measures of insulin sensitivity obtained from hyperinsulinemic euglycemic clamp tests, and in responses to oral glucose tolerance and meal tolerance tests wherein plasma glucose, insulin, and free fatty acid levels (meal tolerance tests only) will be assessed. Further, HbA1c levels and fasting levels of plasma glucose, insulin, and free fatty acids will be assessed periodically throughout the study, and changes from baseline will be statistically analyzed.